Someone on this forum suggested this might be a Fooltone '70 clone and as these sell for peanuts, i wanted to try one. Came in the mail today. Fooltone '70 - bullshit. It's a basic Si FF with rheostat in front of it. Sounds horrible. To call this abysmal would be a praise. Highly moddable, but still. Surely worth 20€ shipped, but still.

I only forgot to put the 100pF capacitor between the Base and Collector of the first transistor in the schematic. It both cuts out the oscillation of the circuit at high gains, and smooths the treble a little. You might want to play with the value to reach the type of sound you're looking for, but I do recommend adding that capacitor for a more stable circuit!

After a little more fiddling, I ended up returning the 22k Collector resistor into place, and replacing the 4k7 resistor with a 560R one, which really make the circuit sound like a classic Fuzz. Everything is staying in place, but I'm arguing, with myself if I should change the blue LED with some other color.